Association between frailty and acute kidney injury after cardiac surgery: unraveling the moderation effect of body fat through an international, retrospective, multi-cohort study.

BACKGROUND: Acute kidney injury (AKI) is a common and serious complication after cardiac surgery that significantly affects patient outcomes. Given the limited treatment options available, identifying modifiable risk factors is critical. Frailty and obesity, two heterogeneous physiological states, have significant implications for identifying and preventing AKI. Our study investigated the interplay among frailty, body composition, and AKI risk after cardiac surgery to inform patient management strategies. MATERIAL AND METHODS: This retrospective cohort study included three international cohorts. Primary analysis was conducted in adult patients who underwent cardiac surgery between 2014 and 2019 at Wuhan XX Hospital, China. We tested the generalizability of our findings with data from two independent international cohorts, the Medical Information Mart for Intensive Care IV (MIMIC-IV) and the eICU Collaborative Research Database. Frailty was assessed using a clinical lab-based frailty index (FI-LAB), while total body fat percentage (BF%) was calculated based on a formula accounting for BMI, sex, and age. Logistic regression models were used to analyze the associations between frailty, body fat, and AKI, adjusting for pertinent covariates. RESULTS: A total of 8785 patients across three international cohorts were included in the study. In the primary analysis of 3,569 patients from Wuhan XX Hospital, moderate and severe frailty were associated with an increased AKI risk after cardiac surgery. Moreover, a nonlinear relationship was observed between body fat percentage and AKI risk. When stratified by the degree of frailty, lower body fat correlated with a decreased incidence of AKI. Extended analyses using the MIMIC-IV and eICU cohorts (n=3,951 and n=1,265, respectively) validated these findings and demonstrated that a lower total BF% was associated with decreased AKI incidence. Moderation analysis revealed that the effect of frailty on AKI risk was moderated by the body fat percentage. Sensitivity analyses demonstrated results consistent with the main analyses. CONCLUSION: Higher degrees of frailty were associated with an elevated risk of AKI following cardiac surgery, and total BF% moderated this relationship. This research underscores the significance of integrating frailty and body fat assessments into routine cardiovascular care to identify high-risk patients for AKI and implement personalized interventions to improve patient outcomes.

Comparison of Four Machine Learning Techniques for Prediction of Intensive Care Unit Length of Stay in Heart Transplantation Patients.

Background: Post-operative heart transplantation patients often require admission to an intensive care unit (ICU). Early prediction of the ICU length of stay (ICU-LOS) of these patients is of great significance and can guide treatment while reducing the mortality rate among patients. However, conventional linear models have tended to perform worse than non-linear models. Materials and Methods: We collected the clinical data of 365 patients from Wuhan Union Hospital who underwent heart transplantation surgery between April 2017 and August 2020. The patients were randomly divided into training data (N = 256) and test data (N = 109) groups. 84 clinical features were collected for each patient. Features were validated using the Least Absolute Shrinkage and Selection Operator (LASSO) regression's fivefold cross-validation method. We obtained Shapley Additive explanations (SHAP) values by executing package "shap" to interpret model predictions. Four machine learning models and logistic regression algorithms were developed. The area under the receiver operating characteristic curve (AUC-ROC) was used to compare the prediction performance of different models. Finally, for the convenience of clinicians, an online web-server was established and can be freely accessed via the website https://wuhanunion.shinyapps.io/PredictICUStay/. Results: In this study, 365 consecutive patients undergoing heart transplantation surgery for moderate (NYHA grade 3) or severe (NYHA grade 4) heart failure were collected in Wuhan Union Hospital from 2017 to 2020. The median age of the recipient patients was 47.2 years, while the median age of the donors was 35.58 years. 330 (90.4%) of the donor patients were men, and the average surgery duration was 260.06 min. Among this cohort, 47 (12.9%) had renal complications, 25 (6.8%) had hepatic complications, 11 (3%) had undergone chest re-exploration and 19 (5.2%) had undergone extracorporeal membrane oxygenation (ECMO). The following six important clinical features were selected using LASSO regression, and according to the result of SHAP, the rank of importance was (1) the use of extracorporeal membrane oxygenation (ECMO); (2) donor age; (3) the use of an intra-aortic balloon pump (IABP); (4) length of surgery; (5) high creatinine (Cr); and (6) the use of continuous renal replacement therapy (CRRT). The eXtreme Gradient Boosting (XGBoost) algorithm presented significantly better predictive performance (AUC-ROC = 0.88) than other models [Accuracy: 0.87; sensitivity: 0.98; specificity: 0.51; positive predictive value (PPV): 0.86; negative predictive value (NPV): 0.93]. Conclusion: Using the XGBoost classifier with heart transplantation patients can provide an accurate prediction of ICU-LOS, which will not only improve the accuracy of clinical decision-making but also contribute to the allocation and management of medical resources; it is also a real-world example of precision medicine in hospitals.

[Progress in the Role of Mechanical Stimulus in Cardiac Development].

Mechanical stimulus is critical to cardiovascular development during embryogenesis period.The mechanoreceptors of endocardial cells and cardiac myocytes may sense mechanical signals and initiate signal transduction that induce gene expression at a cellular level,and then translate molecular-level events into tissue-level deformations,thus guiding embryo development.This review summarizes the regulatory roles of mechanical signals in the early cardiac development including the formation of heart tube,looping,valve and septal morphogenesis,ventricular development and maturation.Further,we discuss the potential mechanical transduction mechanisms of platelet endothelial cell adhesion molecule 1-vascular endothelial-cadherin-vascular endothelial growth factor receptor 2 complex,primary cilia,ion channels,and other mechanical sensors that affect some cardiac malformations.

Outcomes of Three Different Minimal Invasive Approaches for Secundum Atrial Septal Defect Closure: A Single Institute Experience.

OBJECTIVE: The aims of this retrospective study were to investigate and evaluate the safety and efficacy of three approaches for closure of secundum atrial septal defect (ASD). METHODS: In this study, we reviewed clinical data for transcatheter occlusion (TCO, n=63), transthoracic occlusion (TTO, n=55), and right anterolateral minithoracotomy (RALT, n=60) techniques used for ASD closure. We compared the safety and efficacy of the three approaches. RESULTS: ASD size in the TTO group was similar to that in the RALT group (P=0.645) and significantly larger than that in the TCO group (P<0.001). The RALT group had more non-central types of ASD than the TTO and TCO groups (P=0.019 and P<0.001). The operative time in the TTO group was shorter than that in the TCO and RALT groups (P<0.001 and P<0.001). The ventilation time and intensive care unit duration were shorter in the TTO group than in the RALT group (P<0.001 and P<0.001). Hospital duration in the TCO group was shorter than that in the TTO and RALT groups (P<0.001 and P<0.001). There were no residual shunt and mortality in any group in hospital or during follow-up. There was no significant difference in the incidence of total complications among the three groups (P=0.738). CONCLUSION: TCO, TTO, and RALT can be performed with favorable cosmetic and clinical results for closing ASD. Appropriate patient selection is an important factor for successful closure. These techniques are promising alternatives to standard median sternotomy and merit additional study.

Transcatheter tricuspid valve replacement in patients with severe tricuspid regurgitation.

OBJECTIVE: Tricuspid regurgitation (TR) is a common valvular heart disease with unsatisfactory medical therapeutics and high surgical mortality. The present study aims to evaluate the safety and effectiveness of transcatheter tricuspid valve replacement (TTVR) in high-risk patients with severe TR. METHODS: This was a compassionate multicentre study. Between September 2018 and November 2019, 46 patients with TR who were not suitable for surgery received compassionate TTVR under general anaesthesia and the guidance of trans-oesophageal echocardiography and fluoroscopy in four institutions. Access to the tricuspid valve was obtained via a minimally invasive thoracotomy and transatrial approach. Patients' data at baseline, before discharge, 30 days and 6 months after the procedure were collected. RESULTS: All patients had severe TR with vena contracta width of 12.6 (11.0, 14.5) mm. Procedural success (97.8%) was achieved in all but one case with right ventricle perforation. The procedural time was 150.0 (118.8, 180.0) min. Intensive care unit time was 2.0 (1.0, 4.0) days. 6-month mortality was 17.4%. Device migration occurred in one patient (2.4%) during follow-up. Transthoracic echocardiography at 6 months after operation showed TR was significantly reduced (none/trivial in 33, mild in 4 and moderate in 1) and the primary safety end point was achieved in 38 cases (82.6%). Patients suffered from peripheral oedema and ascites decreased from 100.0% and 47.8% at baseline to 2.6% and 0.0% at 6 months. CONCLUSIONS: The present study showed TTVR was feasible, safe and with low complication rates in patients with severe TR.

Which is the best prosthesis in an isolated or combined tricuspid valve replacement?

OBJECTIVES: The debate concerning the optimal choice of tricuspid position continues. We compared the long-term results of mechanical and biological prostheses in patients who underwent isolated or combined tricuspid valve replacement, at 2 major cardiac surgical centres in central China. METHODS: From January 1999 to December 2018, 338 patients underwent tricuspid valve replacement. Patients were divided into an isolated group or a combined group according to whether their surgery was combined with a left heart valve surgery. Mechanical tricuspid valve replacement was performed in 142 patients (isolated group: 41 vs combined group: 101), and 196 patients underwent bioprosthetic tricuspid valve replacement (isolated group: 145 vs combined group: 51). Operative results, long-term survival and tricuspid valve-related events were compared. RESULTS: Early mortality in the combined group was higher (n = 6, 4%) than that in the isolated group (n = 3, 2%), but no significant difference was observed between the mechanical and biological subgroups. In the isolated group, there was a higher event-free rate in the biological subgroup than in the mechanical subgroup (P = 0.042) and a similar result was also observed for patients without Ebstein's anomaly (P = 0.039). In the combined group, no significant difference was observed (P = 0.98). Survival rates were similar between the mechanical and biological subgroups in both the isolated (P = 0.54) and combined (P = 0.81) groups. Mechanical valves in isolated tricuspid valve replacement were more prone to valve thrombosis and bleeding. CONCLUSIONS: Every decision regarding tricuspid valve prostheses should be individualized, but biological prostheses may be an optimal choice for patients, especially for patients without Ebstein's anomaly, in isolated tricuspid valve replacement.

Aß40 Promotes the Osteoblastic Differentiation of Aortic Valve Interstitial Cells through the RAGE Pathway.

Amyloid beta (Aß) peptide 40 enhances the activation of receptor for advanced glycation end products (RAGE) in immune-inflammatory diseases. RAGE exhibits several effects in the setting of numerous cardiovascular events. We hypothesized that the Aß40/RAGE pathway is involved in the osteoblastic differentiation of the valvular interstitial cell (VIC) phenotype, and RAGE knockout intervention could reduce the calcification of aortic valve interstitial cells (AVICs) by inhibiting the extracellular-regulated kinase1/2 (ERK1/2)/nuclear factor kappa-B (NF-κB) signaling pathway. To test this hypothesis, the activation of Aß40/RAGE pathway in human calcific AVs was evaluated with immunohistochemical staining. Cultured calcific VIC models were used in vitro. The VICs were stimulated using Aß40, with or without RAGE small interfering ribonucleic acid (siRNA), and ERK1/2 and NF-κB inhibitors for analysis. Our data revealed that Aß40 induced the ERK1/2/NF-κB signaling pathway and osteoblastic differentiation of AVICs via the RAGE pathway in vitro.

Clinical Application of Bioprosthesis in China: Current Status and Future.

China is one of the countries which have a high incidence of heart valvular disease, but the use of biological valve is limited in China before because the majority of patients are young patients suffering from rheumatic heart disease. The biological valve has a good application prospect in China. On the one hand, the new generation of biological valves have been significantly improved in the aspects of anti-calcification treatment, anti-metabolism, material quality control, valve frame mechanics design, and leaflet sewing technology, and the application effect is improved; on the other hand, surgeons should adapt to the new concept changes, and correctly understand and rationally apply biological valves, master valve repair, atrial fibrillation ablation and other techniques, combined with interventional, minimally invasive techniques, etc., according to the specific conditions of the disease and choose the surgery type to ensure the patients' long-term life quality.

Role of TGF-ß1 Signaling in Heart Valve Calcification Induced by Abnormal Mechanical Stimulation in a Tissue Engineering Model.

A tissue engineering model of heart valve calcification induced in a bioreactor was established to evaluate the calcification induced by abnormal mechanical stimulation and explore the underlying molecular mechanisms. Polyethylene glycol (PEG)-modified decellularized porcine aortic leaflets seeded with human valve interstitial cells (huVICs) were mounted on a Ti-Ni alloy frame to fabricate two-leaflet and threeleaflet tissue engineered valves. The two-leaflet model valves were exposed to abnormal pulsatile flow stimulation with null (group A), low (1000 mL/min, group B), medium (2000 mL/min, group C), and high velocity (3000 mL/min, group D) for 14 days. Morphology and calcification were assessed by von Kossa staining, alkaline phosphatase (ALP) content, and Runx2 immunostaining. Leaflet calcification and mRNA and protein expression of transforming growth factor (TGF)-ß1, bone morphogenetic protein 2 (BMP2), Smad1, and MSX2 were measured at different time points. ALP content was examined in two-leaflet valves seeded with BMP2 shRNA plasmid-infected huVICs and exposed to the same stimulation conditions. The results showed that during 14 days of flow stimulation, huVICs on the leaflet surface proliferated to generate normal monolayer coverage in groups A, B, and C. Under mechanical stimulation, huVICs showed a parallel growth pattern in the direction of the fluid flow, but huVICs exhibited disordered growth in the high-velocity flow environment. von Kossa staining, ALP measurement, and immunohistochemical staining for Runx2 confirmed the lack of obvious calcification in group A and significant calcification in group D. Expression levels of TGF-ß1, BMP2, and MSX2 mRNA and protein were increased under fluid stimulation. ALP production by BMP2 shRNA plasmid-infected huVICs on model leaflets was significantly reduced. In conclusion, abnormal mechanical stimulation in a bioreactor induced calcification in the tissue engineering valve model. The extent of calcification correlated positively with the flow velocity, as did the mRNA and protein levels of TGF-ß1, BMP2, and MSX2. These findings indicate that TGF-ß1/BMP2 signaling is involved in valve calcification induced by abnormal mechanical stimulation.

New Nano-Film Single-Rivet Patent Ductus Arteriosus Occluders: A Prospective, Randomized and Double-blind Study.

Nitinol alloy occluders are widely used in the transcatheter intervention treatment of congenital heart diseases like patent ductus arteriosus (PDA). However, nitinol alloy contains high levels of nickel, which can lead to toxic effects in the immune and hematopoietic systems if released in sufficient quantities. A new type of single-rivet occluder coated with nano-film has been developed to limit the release of nickel. In total, 23 patients were recruited and randomly assigned to the experimental group (n=12) with the new nano-film single-rivet occluders or the control group (n=11) with the traditional occluders. One case in the control group was lost to follow-up. The remaining 22 cases were followed up at 24 h, 7 days, 1 month, 3 months, and 6 months after the procedure. There were no statistically significant differences in routine blood test, alanine aminotransferase, creatinine, and troponin between the experimental and control groups. Serum nickel concentration in both two groups increased at 24 h after the procedure, peaked at 1 month, and returned to preoperative levels at 6 months. Serum nickel levels in the experimental group were significantly lower than in the control group at 24 h, 7 days, 1 month, and 3 months after the procedure. These data suggested that the nano-film coating effectively prevented nickel release from the new occluders, and therefore has a preferable safety profile.

Application of Endoscopic Vein Harvesting in Obese Patients Undergoing Coronary Artery Bypass Grafting.

This study aims to evaluate the clinical outcomes of endoscopic vein harvesting (EVH) for coronary artery bypass grafting (CABG) in obese patients. Totally, 153 obese patients who underwent EVH (n=81) or standard bridging technique (SBT, n=12) in CABG surgery from May 2012 to October 2014 in our hospital were enrolled in this retrospective non-randomized controlled study. The general situation of operation, postoperative complications and short medium-term outcomes were analyzed. The baseline characteristics were similar between these two groups (P>0.05). There were no statistical differences in total operation time (226±28 min vs. 224±30 min, P>0.05), number of damaged vessels (0.12±0.05 vs. 0.16±0.06,P>0.05) and short medium-term outcomes including revascularization rate (1.25% vs. 2.78%, i 0.05), vessel dysfunction rate (11.25% vs. 11.11%,P>0.05) and mortality (0.00% v . 0.00%, P>0.05). Use of EVH was associated with significant reduction of total harvesting time (41 ±6 min vs. 63± 11 min, P<0.05), incision length (4.4±1.1 cm 18.2±4.5 cm, P<0.05) and postoperative lower extremity complications (P<0.05). EVH can reduce the risk of wound complications, whereas does not influence short- and medium-term outcomes in obese patients. It can be considered a reliable procedure of harvesting vessel conduits for obese patients undergoing CABG.

Right Anterolateral Minithoracotomy versus Median Sternotomy Approach for Resection of Left Atrial Myxoma.

BACKGROUND: Minimally invasive surgery has become the standard approach for several cardiac diseases. In this retrospective study, we compared right anterolateral minithoracotomy (RALT) with standard median sternotomy (SMS) for resection of left atrial myxoma (LAM). MATERIALS AND METHODS: From January 2009 to June 2015, the clinical data of patients who underwent RALT (n = 30) and SMS (n = 36) for resection of LAM in our hospital were collected. The preoperative clinical data and operative results were compared between the two groups. RESULTS: There were no significant differences in aortic cross-clamp and cardiopulmonary bypass time between the two groups. The total incision length was significantly shorter in RALT group compared with SMS group (p < 0.001). For RALT and SMS groups, respectively, the intensive care unit length of stay was 29.2 ± 6.5 versus 43.5 ± 6.9 hours (p < 0.001), and the postoperative hospital length of stay was 5 days (interquartile range [IQR]: 4-6) versus 8 days (IQR: 7-10) (p < 0.001). The total cost in RALT group was 27,000 RMB (IQR: 25,000-29,000) versus 33,000 RMB (IQR: 31,000-35,000) in SMS group (p < 0.001). There were no significant differences in mortality and postoperative complications between the two groups. CONCLUSION: RALT approach for LAM resection can be performed safely with favorable cosmetic outcome, accepted clinical results, and lower cost. It should be considered as a promising alternative to SMS and merit additional study.

Efficacy of Bosentan in patients after Fontan procedures: a double-blind, randomized controlled trial.

Fontan surgery is a widely used palliative procedure that significantly improves the survival period of patients with complex congenital heart disease (CHD). However, it does not decrease postoperative complication rate. Previous studies suggested that elevated mean pulmonary artery pressure (mPAP) and vascular resistance lead to decreased exercise tolerance and myocardial dysfunction. Therapy with endothelial receptor antagonists (Bosentan) has been demonstrated to improve the patients' prognosis. A double-blind, randomized controlled trial was performed to explore the efficacy of Bosentan in treating patients who underwent the Fontan procedure. Eligible participants were randomly divided into Bosentan group and control group. Liver function was tested at a local hospital and the results were reported to the phone inspector every month. If the results suggested abnormal liver function, treatment would be adjusted or terminated. All the participants finished the follow-up study, with no patients lost to follow-up. Unblinding after 2-year follow-up, no mortality was observed in either group. However, secondary end-points were found to be significantly different in the comparable groups. The cardiac function and 6-min walking distance in the Bosentan group were significantly superior to those in the control group (P=0.018 and P=0.027). Bosentan could improve New York Heart Association (NYHA) functional status and improve the results of the 6-min walking test (6MWT) in Fontan patients post-surgery, and no other benefits were observed. Furthermore, a primary meta-analysis study systematically reviewed all the similar clinical trails worldwide and concluded an overall NYHA class improvement in Fontan patients who received Bosentan treatments.

Should a Mechanical or Biological Prosthesis Be Used for a Tricuspid Valve Replacement? A Meta-Analysis.

BACKGROUND AND AIM OF THE STUDY: The prosthesis of choice for a tricuspid valve replacement is still unkown. This meta-analysis was undertaken to review the results of mechanical and bioprosthetic valves in the tricuspid position. METHODS: We identified all relevant studies published in the past 20 years (from January 1, 1995 to December 31, 2014) through the Embase, Current Contents, and PubMed databases. The hazard ratio and its 95% confidence limits were utilized to evaluate time-to-event related effects of surgical procedures. The Q-statistic, Index of Inconsistency test, funnel plots, and Egger's test were used to assess the degree of heterogeneity and publication bias. Random effects models were used, and study quality was also assessed. RESULTS: In our meta-analysis, 22 studies published from 1995 to 2014 were reviewed and 2630 patients and 14,694 follow-up years were analyzed. No statistically significant difference was identified between mechanical and biological valves in terms of survival, reoperation, and prosthetic valve failure. The respective pooled hazard ratio estimates were 0.95 (0.79 to 1.16, p = 0.62, I(2) = 29%), 1.20 (0.84 to 1.71, p = 0.33, I(2) = 0%), and 0.35 (0.06 to 2.01, p = 0.24, I(2) = 0%). A higher risk of thrombosis was found in mechanical tricuspid valve prostheses (3.86, 1.38 to 10.82, p = 0.01, I(2) = 0%). CONCLUSIONS: No statistically significant difference was identified between mechanical and biological valves in terms of survival, reoperation, or prosthetic valve failure, but mechanical tricuspid valve prostheses had a higher risk of thrombosis. doi: 10.1111/jocs.12730 (J Card Surg 2016;31:294-302).

Pediatric Heart Transplantation: Report from a Single Center in China.

BACKGROUND: Although heart transplantation (HTx) has become a standard therapy for end-stage heart diseases, experience with pediatric HTx is limited in China. In this article, we will try to provide the experience with indications, complications, perioperative management, immunosuppressive therapy, and survival for pediatric HTx based on our clinical work. METHODS: This is a retrospective chart review of the pediatric patients undergoing HTx at Department of Cardiovascular Surgery of Union Hospital from September 2008 to December 2014. We summarized the indications, surgical variables, postoperative complications, and survival for these patients. RESULTS: Nineteen pediatric patients presented for HTx at Union Hospital of Tongji Medical College, of whom 10 were male. The age at the time of transplantation ranged from 3 months to 18 years (median 15 years). Patient weight ranged from 5.2 kg to 57.0 kg (median 38.0 kg). Pretransplant diagnosis included cardiomyopathy (14 cases), complex congenital heart disease (3 cases), and tumor (2 cases). All recipients received ABO-compatible donor hearts. Postoperative complications occurred in 12 patients, including cardiac dysfunction, arrhythmia, pulmonary infection, renal dysfunction, and rejection. Two of them experienced cardiac failure and required extracorporeal membrane oxygenation. The immunosuppression regimen was comprised of prednisone, a calcineurin inhibitor, and mycophenolate. All patients recovered with New York Heart Association (NYHA) Class I-II cardiac function and were discharged. Only one patient suffered sudden death 19 months after transplantation. CONCLUSION: Orthotopic HTx is a promising therapeutic option with satisfying survival for the pediatric population in China with end-stage heart disease.

Secretion of adipocytes and macrophages under conditions of inflammation and/or insulin resistance and effect of adipocytes on preadipocytes under these conditions.

The purpose of the present study was to examine changes in preadipocytes following the coculture of preadipocytes and adipocytes and the effects on the secretion of adipocytes and macrophages following induction of inflammation and insulin resistance. Mature adipocytes and RAW264.7 macrophages were treated with lipopolysaccharide and insulin to establish models of inflammation and insulin resistance, respectively. The mRNA expression levels of IL-6, MCP-1, and TNF-α in all adipocyte treatment groups were significantly greater compared with the control, and that of adiponectin was less (P<0.05). In the RAW264.7 macrophages, the mRNA expression levels of IL-6 and TNF-α were greater than those in the control group (P<0.05). Moreover, the results of this study confirmed that adipocytes and macrophages increased the secretion of inflammatory factors under conditions of induced inflammation and insulin resistance. In addition, 3T3-L1 adipocytes inhibited the proliferation and differentiation of preadipocytes when cocultured with adipocytes under conditions of inflammation and/or insulin resistance, and the phenotype of preadipocytes did not change.